Means for cooling stator vane assemblies



May 28, 1957 J. B. WHEATLEY ET AL 2,793,832

MEANS FOR COOLING sTA'rOR VANE AssEMBLIEs May 28, 1957 J. B. WHEATLEY ETAL 2,793,832

MEANS FOR COOLING sTAToR vANE AssEMBLIEs med April so, 1952 2 sheets-sheet 2 INVENTORS BY l / ATTORNEYS MEANS FOR COOLING STAT OR VANE ASSEMBLIES John B. Wheatley and Donald G. Zimmerman, Indianapolis, Ind., assignors to General-Motors Corporation, Detroit, Mich., a corporation of Delaware Application April 30, 1952, Serial No. 285,170 s Claims. (Cl. 25a-39.1)

This invention relates to turbine cooling and more particularly to means for air cooling the stator vane assemblies of an axial ow gas turbine.

An object of this invention is to provide means in a turbine whereby a shroud ring and/ or its associated stator vanes are bathed by a suitable cooling fluid.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred form of the invention is clearly shown.

In the drawings:

Figure l is a longitudinal section of a portion of a gas turbine constructed in accordance with my invention; and Figure 2 is a fragmentary section taken substantially along the line 2--2 of Figure l.

Referring now to the drawings in detail, Figure l shows a portion of an axial flow gas turbine combustion apparatus that includes an outer shell 10, an inner shell 12, and one of a number of flame tubes 16 that are mounted between the shells and 12 in the annular space 14. The after portion of the llame tube 16 is connected to a first stage stator assembly or nozzle 18 by a transition tube 20. In accordance with the usual practice, a turbine driven compressor (not shown) feeds air to the combustion apparatus where combustion is effected in the flame tubes, the motive fluid being fed by the transition tubes to the turbine to drive the same. The compressor also feeds the space 14 with cooling air, for the combustion apparatus is supplied with an excess of air over that required for combustion. In accordance with my invention, I tap some of this cooling air, circulate it through the turbine stator, and bleed it through the hollow stator vanes before passing it into the motive gas stream.

The external turbine casing 22 is composed of a series of radially anged rings that are bolted together, as at 24 and 26, and to the shell 10, as at 28. I have illustrated my invention as applied to the first and second stages of a gas -turbine but it should be realized that it may be applied to as many stages as are required by a particular installation. The first stage stator Vane assembly or nozzle 18 includes an outer shroud ring 30 supported in the casing 22 by slotted radial flanges 32 and 34, and an inner shroud ring 36 fixed to the ring 30 by a series of radially extending stator vanes 38 which are suitably welded to the shroud rings. The stator vanes are hollow, are open at the ends that extend through and are welded :to the outer shroud ring, and are closed at the ends that are welded to the inner shroud ring.

The second stage stator assembly includes an outer shroud ring 40 interlocked to the casing 22 and the ring 30 by the radial anges 42 and 44 and an inner shroud ring 46 supported from the ring 40 by the stator vane 48, the inner shroud ring 46 forming a conventional seal with the rim of the turbine spacer disk 50. The stator vane assemblies tend to expand more than the casing 22 so it is desirable to segment the assemblies along planes extending longitudinally of the turbine axis and to provide 2,793,832 Patented May 28, 1957 some'clearancev between the segments so that they may expand peripherally. The segments are circumferentially located by cap screws, such as are shown at 49 and 51, that are threaded through the casing 22 and extend into bosses on the outer shroud rings.

The turbine rotor is of the multiple disk type. Only the forward portion that includes the turbine bearing cooling fan 52, the turbine blade disks 54 and 56, and the spacer disk 50 is shown, the parts not shown being irnmaterial to an understanding of this invention. The rim of the disk 54 is cooled by air which is bled from the space 14 past the ring seal 58 that is carried by the ring seal support 60 as described and claimed in a copending application of Zimmerman for Turbine Rotor Assembly,

ICC,

Serial Number 283,611, filed April 22, 1954. The sup# port 60 also carries turbine rotor seals 62 and 64 and is bolted to the turbine bearing housing 66 at 68.

In operation, cooling air is bled from the annular space 14 through the slots 70 in fthe flange 32, through the annular air space 74, through the mating slots 72 of the flanges 34 and 44, and into the annular air space 76 between the outer shroud ring and the casing 22. The hollow stator vanes 38 and 48 open into the air spaces 74 and 76 at 75 and 77. The cooling air ows the length of the vanes and is discharged into the motive fluid path through holes 78 and 80 in one or both sides of the vanes above the inner shrouds. The holes 78 and 80 may be conveniently formed by slotting across the ends of the stator vanes.

While the form of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms may be devised by the exercise of skill in the art, and the invention is not to be regarded as limited by the detailed description.

We claim:

l. An elastic fluid turbine comprising an external casing encircling the blade system of the turbine, first and second stator vane assemblies in said casing including hollow vanes extending radially inward from lirst and second outer shroud rings that dene an annular motive fluid duct, a peripheral flange on said first shroud ring extending radially outward and terminating in a longitu dinally extending tongue engaged in a longitudinally extending peripheral groove in said casing for supporting said rst assembly in spaced relation within said casing so as to define a rst annular chamber around said duct, means for supporting said second assembly in spaced relation within said casing so as to define a second annular chamber around said duct, said first shroud ring ange being longitudinally slotted at peripherally spaced points to place said irst and second chambers-in communication with each other, and means for feeding cooling liuid into said first chamber for distribution to said second chamber by way of said slotted flange, said hollow vanes opening into said chambers and receiving cooling uid therefrom.

2. An elastic fluid turbine comprising an external casing encircling the blade system of the turbine, first and second stator vane assemblies in said casing including hollow vanes extending radially inward from tirst and second outer shroud rings that deline an annular motive uid duct, a peripheral flange on said iirst shroud ring extending radially outward and terminating in a longitudinally extending tongue engaged in a longitudinally extending peripheral groove in said casing for supporting said rst assembly in spaced relation within said casing so as to define a first annular chamber around said duct, a peripheral ange on said second shroud ring extending radially outward and terminating in a longitudinally extending tongue for supporting said second assembly in spaced relation within said casing so as to define a second annular chamber around said duet, said first and second shroud ring flanges being longitudinally slotted at peripherally spaced points to place said iirst and second chambers in communication with each other, and means for feeding cooling uid into said first chamber for distribution to said second chamber by way of said slotted anges, said hollow vanes opening into said chambers and receiving cooling uid therefrom.

3. An elastic iiuid turbine comprising an external casing encircling the blade system of the turbine, `first and second stator vane assemblies in said casing including hol low vanes extending radially inward from first and second outer shroud rings in abutting end to end relation with each other that define an annular'motive fluid duct, a per'ipheral ange on said first shroud ring slightly spaced from the abutting end thereof to form a peripheral ledge and extending radially outward and terminating in a longitudinally extending tongue engaged in a longitudinally extending peripheral groove in said casing for supporting said first assembly in spaced relation within said casing so as to define a rst annular chamber around said duct, a peripheral flange on said second shroud ring at the abutting end thereof extending radially outward and terminating in a longitudinally extending tongue engaged between said ledge of said first shroud ring and the inner wall of said casing for supporting said second assembly in spaced relation within lsaid casing so as to define a second annular chamber around said duct, said first and second shroud ring flanges being longitudinally slotted at peripherally spaced points to place said first and second chambers in communication with each other, and means for feeding cooling iluid into said first chamber for distribution to said second chamber by way of said slotted anges, said hollow varies opening into said chambers and receiving cooling uid therefrom.

References Cited in the tile of this patent UNITED STATES PATENTS 2,445,661 Constant et al July 20, 1948 2,506,581 Cowles May 9, 1950 2,563,269 Price Aug. 7, 1951 2,567,249 Stalker Sept. l1, 1951 2,584,899 McLeod Feb. 5, 1952 2,599,470 Meyer June 3, 1952 2,625,013 Howard et al Ian. 13, 1953 2,625,367 Rainbow et al. lan. 13, 1953 2,625,793 Mierley et al Jan. 20, 1953 2,640,319 Wislincenus June 2, 1953 

